Electrophotographic member having elastic layer with elastic modulus of 0.5 to 3.0 MPA and coating layer with elastic modulus of 5.0 to 100 MPA

Abstract

An electrophotographic member has an electro-conductive substrate, an elastic layer on the substrate and a coating layer on the elastic layer. The elastic layer has an elastic modulus of 0.5 MPa to 3.0 MPa and the coating layer has an elastic modulus of 5.0 MPa to 100.0 MPa as measured in an environment of a temperature of 30° C. and a relative humidity of 80%.

What is claimed is: 
     
       1. An electrophotographic member comprising an electro-conductive substrate, an elastic layer on the substrate and a coating layer on the elastic layer, wherein
 the elastic layer has a first protrusion on a surface thereof on a side opposite to a side facing the substrate, 
 the electrophotographic member has, on an outer surface thereof, a second protrusion derived from the first protrusion, 
 the outer surface of the electrophotographic member has one or more of electrical insulating first region(s) and an electro-conductive second region, 
 the elastic layer has an elastic modulus, as measured in an environment of a temperature of 30° C. and a relative humidity of 80%, of 0.5 MPa or more to 3.0 MPa or less and 
 the coating layer has an elastic modulus, as measured in an environment of a temperature of 30° C. and a relative humidity of 80%, of 5.0 MPa or more to 100.0 MPa or less. 
 
     
     
       2. The electrophotographic member according to  claim 1 , wherein the first region has an electrical insulating part on a surface of the coating layer on a side opposite to a side facing the substrate. 
     
     
       3. The electrophotographic member according to  claim 2 , wherein the electrical insulating part contains a resin. 
     
     
       4. The electrophotographic member according to  claim 2 , wherein the electrical insulating part has an elastic modulus larger than the elastic modulus of the coating layer. 
     
     
       5. The electrophotographic member according to  claim 1 , wherein the coating layer is an electro-conductive and the second region has a portion of a surface of the coating layer on a side opposite to a side facing the substrate. 
     
     
       6. The electrophotographic member according to  claim 5 , wherein the coating layer has a volume resistivity of from 1×10 5  to 1×10 11  Ω·cm. 
     
     
       7. The electrophotographic member according to  claim 2 , wherein the electrical insulating part has a volume resistivity of from 1×10 13  to 1×10 18  Ω·cm. 
     
     
       8. The electrophotographic member according to  claim 1 , further comprising an electro-conductive surface layer on a surface of the coating layer on a side opposite to a side facing the substrate, wherein:
 the surface layer comprises, on a surface thereof on a side opposite to a side facing the coating layer, an electrical insulating region and an electro-conductive region, 
 the electrical insulating region constitutes the first region and 
 the electro-conductive region constitutes the second region. 
 
     
     
       9. The electrophotographic member according to  claim 8 , wherein the electrical insulating region has an elastic modulus larger than the elastic modulus of the coating layer. 
     
     
       10. The electrophotographic member according to  claim 8 , wherein the surface layer has an electrical insulating part constituting the first region and an electro-conductive part constituting the second region. 
     
     
       11. The electrophotographic member according to  claim 10 , wherein the electrical insulating part has a volume resistivity of from 1×10 13  to 1×10 18  Ω·cm. 
     
     
       12. The electrophotographic member according to  claim 10 , wherein the electro-conductive part has a volume resistivity of from 1×10 5  to 1×10 11  Ω·cm. 
     
     
       13. The electrophotographic member according to  claim 1 , wherein when a surface of the electrical insulating first region constituting the outer surface of the electrophotographic member is charged to a potential V0 (V), a potential damping time constant defined as a time required for damping the surface potential to V0×(1/e) is 60 seconds or more. 
     
     
       14. The electrophotographic member according to  claim 1 , wherein when a surface of the electro-conductive second region constituting the outer surface of the electrophotographic member is charged to a potential V0 (V), a potential damping time constant defined as a time required for damping the surface potential to V0×(1/e) is less than 6.0 seconds. 
     
     
       15. An electrophotographic process cartridge mounted detachably on an electrophotographic image forming apparatus, comprising at least a developing member,
 wherein the developing member has an electrophotographic member and 
 wherein the electrophotographic member has an electro-conductive substrate, an elastic layer on the substrate and a coating layer on the elastic layer, wherein 
 the elastic layer has a first protrusion on a surface thereof on a side opposite to a side facing the substrate, 
 the electrophotographic member has, on an outer surface thereof, a second protrusion derived from the first protrusion, 
 the outer surface of the electrophotographic member has one or more of electrical insulating first region(s) and an electro-conductive second region, 
 the elastic layer has an elastic modulus, as measured in an environment of a temperature of 30° C. and a relative humidity of 80%, of 0.5 MPa or more to 3.0 MPa or less and 
 the coating layer has an elastic modulus, as measured in an environment of a temperature of 30° C. and a relative humidity of 80%, of 5.0 MPa or more to 100.0 MPa or less. 
 
     
     
       16. An electrophotographic image forming apparatus, comprising at least a developing member,
 wherein the developing member has an electrophotographic member and 
 wherein the electrophotographic member has an electro-conductive substrate, an elastic layer on the substrate and a coating layer on the elastic layer, wherein 
 the elastic layer has a first protrusion on a surface thereof on a side opposite to a side facing the substrate, 
 the electrophotographic member has, on an outer surface thereof, a second protrusion derived from the first protrusion, 
 the outer surface of the electrophotographic member has one or more of electrical insulating first region(s) and an electro-conductive second region, 
 the elastic layer has an elastic modulus, as measured in an environment of a temperature of 30° C. and a relative humidity of 80%, of 0.5 MPa or more to 3.0 MPa or less and 
 the coating layer has an elastic modulus, as measured in an environment of a temperature of 30° C. and a relative humidity of 80%, of 5.0 MPa or more to 100.0 MPa or less.